Facts About Pangaea The breakup of the Pangaea supercontinent. Credit: U.S. Geological Survey About 300 million years ago, Earth didn't have seven continents, but instead one massive supercontinent called Pangaea, which was surrounded by a single ocean called Panthalassa. The explanation for Pangaea's formation ushered in the modern theory of plate tectonics , which posits that the Earth's outer shell is broken up into several plates that slide over Earth's rocky shell, the mantle. Over the course of the planet's 3.5 billion-year history, several super continents have formed and broken up, a result of churning and circulation in the Earth's mantle , which makes up most of planet's volume. This breakup and formation of supercontinents has dramatically altered the planet's history. "This is what's driven the entire evolution of the planet through time. This is the major backbeat of the planet," said Brendan Murphy, a geology professor at the St. Francis Xavier University, in Antigonish, Nova Scotia.

History More than a century ago, the scientist Alfred Wegener proposed the notion of an ancient supercontinent, which he named Pangaea (sometimes spelled Pangea), after putting together several lines of evidence. The first and most obvious was that the "continents fit together like a tongue and groove," something that was quite noticeable on any accurate map, Murphy said. Another telltale hint that Earth's continents were all one land mass comes from the geologic record. Coal deposits found in Pennsylvania have a similar composition to those spanning across Poland, Great Britain and Germany from the same time period. That indicates that North America and Europe must have once been a single landmass. And the orientation of magnetic minerals in geologic sediments reveals how Earth's magnetic poles migrated over geologic time, Murphy said. In the fossil record, identical plants, such as the extinct seed fern Glossopteris, are found on now widely disparate continents. And mountain chains that now lie on different continents, such as the Appalachians in the United States and the Atlas Mountains in Morocco, were all part of the Central Pangaea Mountains, formed through the collision of the supercontinents Gondwana and Laurussia.

Pangaea formed through a gradual process spanning a few hundred million years. Beginning about 480 million years ago, a continent called Laurentia, which includes parts of North America, merged with several other micro-continents to form Euramerica. Euramerica eventually collided with Gondwana, another supercontinent that included Africa, Australia, South America and the Indian subcontinent. About 200 million years ago, the supercontinent began to break up. Gondwana (what is now Africa, South America, Antarctica, India and Australia) first split from Laurasia (Eurasia and North America). Then about 150 million years ago, Gondwana broke up. India peeled off from Antarctica, and Africa and South America rifted, according to a 1970 article in the Journal of Geophysical Research . Around 60 million years ago, North America split off from Eurasia. Life and climate Having one massive landmass would have made for very different climactic cycles. For instance, the interior of the continent may have utterly dry, as it was locked behind massive mountain chains that blocked all moisture or rainfall, Murphy said.

But the coal deposits found in the United States and Europe reveal that parts of the ancient supercontinent near the equator must have been a lush, tropical rainforest, similar to the Amazonian jungle, Murphy said. (Coal forms when dead plants and animals sink into swampy water, where pressure and water transform the material into peat, then coal.) "The coal deposits are essentially telling us that there was plentiful life on land," Murphy told Live Science. Pangaea existed for 100 million years, and during that time period several animals flourished, including the Traversodontidae , a family of plant-eating animals that includes the ancestors of mammals. During the Permian period , insects such as beetles and dragonflies flourished. But the existence of Pangaea overlapped with the worst mass extinction in history, the Permian-Triassic (P-TR) extinction event. Also called the Great Dying, it occurred around 252 million years ago and caused most species on Earth to go extinct. The early Triassic period saw the rise of archosaurs, a group of animals that eventually gave rise to crocodiles and birds, and a plethora of reptiles.

And about 230 million years ago some of the earliest dinosaurs emerged on Pangaea, including theropods, largely carnivorous dinosaurs that mostly had air-filled bones and feathers similar to birds. Cycle in history The current configuration of continents is unlikely to be the last. Supercontinents have formed several times in Earth's history, only to be split off into new continents. Right now for instance, Australia is inching toward Asia, and the eastern portion of Africa is slowly peeling off from the rest of the continent. Geologists have noticed that there is a quasi-regular cycle in which supercontinents form and break up every 300 to 400 million years, but exactly why is a mystery, Murphy said. But most scientists believe that the supercontinent cycle is largely driven by circulation dynamics in the mantle, according to a 2010 article in the Journal of Geodynamics . Beyond that, the details get fuzzy. While the heat formed in the mantle likely comes from the radioactive decay of unstable elements, such as uranium, scientists don't agree on whether there are mini-pockets of heat flow within the mantle, or if the entire shell is one big heat conveyor belt, Murphy said.

Follow Tia Ghose on Twitter and Google+ . Follow LiveScience @livescience , Facebook & Google+ . Additional resources continental drift - National Geographic Society continental drift The way some continents fit together like puzzle pieces inspired the theory of continental drift. Map by USGS Urkontinent Alfred Wegener’s original name for his proposed, ancient continent was “Urkontinent”—ur meaning “first or original,” and kontinent meaning “continent” in Wegener’s native language, German. A more popular name for this huge ancient landmass is Pangaea, which means “all lands” in Greek. Colliding Skyward The collision of the Indian subcontinent and Asian continent created the Himalayan mountain range, home to the world's highest mountain peaks, including 30 that exceed 7300 meters (24,000 feet). Because continental drift is still pushing India into Asia, the Himalayas are still growing. Continental drift describes one of the earliest ways geologist s thought continent s moved over time. Today, the theory of continental drift has been replaced by the science of plate tectonics . The theory of continental drift is most associated with the scientist Alfred Wegener .

In the early 20th century, Wegener published a paper explaining his theory that the continental landmass es were “drifting” across the Earth, sometimes plowing through oceans and into each other. He called this movement continental drift. Pangaea Wegener was convinced that all of Earth’s continents were once part of an enormous , single landmass called Pangaea . Wegener, trained as an astronomer , used biology , botany , and geology describe Pangaea and continental drift. For example, fossil s of the ancient reptile mesosaurus are only found in southern Africa and South America. Mesosaurus, a freshwater reptile only one meter (3.3 feet) long, could not have swum the Atlantic Ocean. The presence of mesosaurus suggests a single habitat with many lakes and rivers. Wegener also studied plant fossils from the frigid Arctic archipelago of Svalbard, Norway. These plants were not the hardy specimen s adapt ed to survive in the Arctic climate . These fossils were of tropical plants, which are adapted to a much warmer, more humid environment. The presence of these fossils suggests Svalbard once had a tropical climate .

Finally, Wegener studied the stratigraphy of different rocks and mountain range s. The east coast of South America and the west coast of Africa seem to fit together like pieces of a jigsaw puzzle , and Wegener discovered their rock layers “fit” just as clearly. South America and Africa were not the only continents with similar geology. Wegener discovered that the Appalachian Mountains of the eastern United States, for instance, were geologically related to the Caledonian Mountains of Scotland. Pangaea existed about 240 million years ago. By about 200 million years ago, this supercontinent began breaking up. Over millions of years, Pangaea separated into pieces that moved away from one another. These pieces slowly assumed their positions as the continent we recognize today. Today, scientists think that several supercontinents like Pangaea have formed and broken up over the course of the Earth’s lifespan. These include Pannotia, which formed about 600 million years ago, and Rodinia, which existed more than a billion years ago. Tectonic Activity Scientists did not accept Wegener’s theory of continental drift.

One of the elements lacking in the theory was the mechanism for how it works—why did the continents drift and what patterns did they follow? Wegener suggested that perhaps the rotation of the Earth caused the continents to shift towards and apart from each other. (It doesn't.) Today, we know that the continents rest on massive slab s of rock called tectonic plate s. The plates are always moving and interacting in a process called plate tectonics. The continents are still moving today. Some of the most dynamic sites of tectonic activity are seafloor spreading zones and giant rift valleys. In the process of seafloor spreading , molten rock rises from within the Earth and adds new seafloor ( oceanic crust ) to the edges of the old. Seafloor spreading is most dynamic along giant underwater mountain ranges known as mid-ocean ridge s. As the seafloor grows wider, the continents on opposite sides of the ridge move away from each other. The North American and Eurasian tectonic plates, for example, are separated by the Mid-Atlantic Ridge . The two continents are moving away from each other at the rate of about 2.5 centimeters (1 inch) per year.

Rift valley s are sites where a continental landmass is ripping itself apart. Africa, for example, will eventually split along the Great Rift Valley system . What is now a single continent will emerge as two—one on the African plate and the other on the smaller Somali plate. The new Somali continent will be mostly oceanic, with the Horn of Africa and Madagascar its largest landmasses. The processes of seafloor spreading, rift valley formation, and subduction (where heavier tectonic plates sink beneath lighter ones) were not well-established until the 1960s. These processes were the main geologic forces behind what Wegener recognized as continental drift. Term to adjust to new surroundings or a new situation. Alfred Wegener (1880-1930) German meteorologist and geologist. ancient person who studies space and the universe beyond Earth's atmosphere. biology always changing or in motion. enormous having to do with a habitat or ecosystem of a lake, river, or spring. frigid person who studies the physical formations of the Earth. geology Noun study of the physical history of the Earth, its composition, its structure, and the processes that form and change it.

Great Rift Valley system Noun series of faults and other sites of tectonic activity stretching from southwestern Asia to the Horn of Africa. habitat strong or able to withstand severe weather. humid air containing a large amount of water vapor. jigsaw puzzle interlocking pieces that, when correctly put together, display a picture or design. landmass process or assembly that performs a function. mesosaurus freshwater reptile that lived during the early Permian period, about 300 million years ago. Mid-Atlantic Ridge underwater mountain range that runs from Iceland to Antarctica. mid-ocean ridge solid material turned to liquid by heat. mountain range series or chain of mountains that are close together. oceanic crust thin layer of the Earth that sits beneath ocean basins. Pangaea supercontinent of all the Earth's landmass that existed about 250 million years ago. plate tectonics movement and interaction of the Earth's plates. reptile animal that breathes air and usually has scales. rift valley flat, thick piece of material such as earth or stone. specimen individual organism that is a typical example of its classification. stratigraphy study of rock layers and layering.

subduction process of one tectonic plate melting, sliding, or falling beneath another. supercontinent ancient, giant landmass that split apart to form all the continents we know today. tectonic plate Noun massive slab of solid rock made up of Earth's lithosphere (crust and upper mantle). Also called lithospheric plate. tropical Adjective existing in the tropics, the latitudes between the Tropic of Cancer in the north and the Tropic of Capricorn in the south. tropical climate 611 - Our One-Continent World: Pangea (Political) | Big Think 611 - Our One-Continent World: Pangea (Political) Over a year ago by Frank Jacobs There's much to criticise about this map of Pangea [1] , but in spite of the geological anachronisms, it's hard to tear your eyes away from it. The map shows a world in which the continents have broken loose from their moorings and crashed into each other in a planet-wide collision. These United Nations of Pangea are a cartographic improbability radiating the lurid attraction of a roadside accident. Ah, the blood, the noise, the endless poetry!

[2] Younger readers may be surprised to learn that this Mother of All Pile-Ups is not mere fiction. The map reconstitutes the world's single supercontinent as it existed between 300 and 200 million years ago [3] - but with one obvious difference: it borrows today's national borders and transposes them on Pangea, dramatically increasing the visual tension between the world as we know it today, and the world as it once was. The past, in this case, is not just a foreign country, but an alien continent. The fascinating thing about this map is that incongruity between this world's familiar nations, and that world's bizarre supercontinent. The incongruity seems designed with that F.

Scott Fitzgerald quote in mind: "The test of a first-rate intelligence is the ability to hold two opposing ideas in mind at the same time and still retain the ability to function." It is one thing to see the continents reassembled into a single block - the stuff of any paleogeological map of Pangea - but quite another to see the US state of Florida hemmed in between the Guyanas [4] and the Guineas [5] ; to witness Antarctica, Australia and the Indian subcontinent conspirationally huddled together in the world's most improbable threesome; to see Newfoundland, on Canada's east coast, function as the wedge that drives Morocco and Spain apart; or to find Iran mercilessly chopped in three, its parts flung far across the Thetys Sea. Surely, a punishment too severe, whatever her sins! Our world's borders greatly improve the visual spectacle of this map. But shoehorning today's countries and continents into the Pangea of eons [6] ago means sacrificing accuracy for recognisability.

For example, even though the Great Lakes and Hudson Bay are firmly anchored to our mental map of North America, and they're present here as well, these great natural phenomena are only immutable from the puny perspective of our short human lifespans. They were formed no longer ago than 10.000 years, after the most recent northward retreat of the glaciers [7] . Geological anachronisms are much easier to ignore, or rather to remove, if they're mere islands out of time. Such should have been the fate of Iceland, one of the youngest countries on earth, geologically speaking: it was thrust up out of the waves of the North Atlantic just under 20 million years ago, on a volcanic hot spot along the Mid-Atlantic Ridge. Yet Iceland is also right there on the map, squeezed between the Hebridean coast of Scotland and the fjord-indented shores of Greenland and Norway. But this map is not meant to be accurate, at least not to that degree. It is a tongue in cheek follow-through of one of the most basic observations one can make while looking at a world map.

It only takes a cursory glance at that map to see that some land masses separated by bodies of water are like linking pieces of a global puzzle. The corresponding coastlines of Madagascar and Mozambique are a suspiciously good fit, as are those of Finland and Sweden. The most obvious example, however, are the Atlantic coasts of South America and Africa. That most striking of correspondences only became apparent after the discovery of America - and after enough progress in mapmaking to enable a faithful rendering of the respective shorelines. It's perhaps no surprise then that a cartographer first remarked on the spooning of these continents. In his Thesaurus Geographicus (1596), Abraham Ortelius proposed that the Americas "were torn away from Europe and Africa […] The vestiges of the rupture reveal themselves, if someone brings forward a map of the world and considers carefully the coasts of the three [continents]". Ortelius may have been right on the effect, he was less than correct on its causes. He suggested that the distancing of the continents was the result of "earthquakes and floods". It took a few centuries for science to get this right. For incredibly, the currently generally accepted theory on continental drift is barely a century old.

The German geophysicist and polar explorer Alfred L. Wegener [8] first hypothesised what he called Kontinentalverschiebung in a series of articles in 1912, and later expanded on the theory of continental drift in the book Die Entstehung der Kontinente und Ozeane (1915). He would refine his arguments in thee more editions of the book, the last one published year before his untimely death on a Greenlandic expedition in 1929, but harvest mainly scorn and derision for his efforts. For a theory that controversial, Wegener's starting points were surprisingly commonplace. Like Ortelius, Wegener took on board the near-perfect fit of South America with Africa. And like a string of 19th-century scientists, he became aware of the similarities in plant life and fossil finds on either side of the South Atlantic. His innovation was to reject the prevailing theory of a sunken land bridge to explain those similarities, instead pushing the hypothesis that the present, separated continents had formed an Urkontinent before drifting apart.

One of Wegener's problems was that he never managed to pinpoint a cause for the drifting, although among the ideas he put forward was the notion that oceanic ridges, like the Mid-Atlantic one on which Iceland is perched, pushed continents out from each other [9] . This notion would form the basis of plate tectonics - the now generally accepted theory that describes how the Earth's lithosphere [10] consists of different plates that slowly collide with, separate from or grind against each other. These activities are responsible for earthquakes, volcanic eruptions and continental drift. Yet it took decades for this theory to gain a serious following. Opposition to Wegener's big idea even gave rise to its opposite, so-called 'permanentism' [11] . The idea of something as solid and massive as a continent moving around just seemed too improbable. But given enough time, considering the relative plasticity even of rocks under enough pressure, and provided with mounting evidence of tectonic plates carrying the continents, drifting and colliding on earth's molten mantle.

Only in the late 1950s and early 1960s, when data from the new discipline of paleomagnetism seemed to prove the theory, did continental drift decisively win the argument. Wegener's Urkontinent is these days better known as Pangea. It may have looked roughly like the land mass portrayed here. Its exact contours are a matter of speculation, but generally it is thought to have looked like the land mass on this map: Africa locked into North and South America to its west, and attached to an amalgam of Antarctica, Australia and India to its southeast, with the remaining Eurasian land mass then twisted on its head to serve as Pangea's hat, and Europe a crescent-shaped smear in between. Surrounding the single continent would be the world's single ocean, Panthalassia. If all of that sounds like a fantastically alien concept this close to home, you're in for a treat: for Pangea and Panthalassia were but the latest incarnations of what may well have been a series of supercontinents and superoceans, continuously breaking up and getting back together as if they were geology's answer to Richard Burton and Elizabeth Taylor.

Here are some other supercontinents, each next one older and more hypothetical than the previous one: Pannotia, a.k.a. the Vendian supercontinent or Greater Gondwanaland, probably formed around 600 million years ago. Around 540 million years ago, it drifted apart into four separate continents: Laurentia, Baltica, Siberia and Gondwana. These would later recombine to form Pangaea. Rodinia [12] may have existed from 1.1 billion to 750 million years ago, or not: another theory/configuration thought to have existed around this time is called Paleo-Pangea (or Proto-Pangea). The super-ocean that surrounded Rodinia (if it existed) is called Mirovia, also a Russian derivation. Columbia (a.k.a. Nuna, or Hudsonland), may have existed from 1.8 to 1.5 billion years ago. Evidence of its existence is based upon geological and paleomagnetic data. Kenorland, formed about 2.7 billion years ago, broke up about 2.1 billion years ago.

The most hypothetical supercontinents are Ur, formed about 3 billion years ago, possibly the world's first continent, if it weren't for the even more hypothetical Vaalbara, formed about 3.6 billion years ago. Considering the evidence of the deep past, and the continued tectonic activity moving continents around, it is indeed likely that at some point in the distant future, our separated continents will re-arrange in a single supercontinent. Three proposed supercontinents that could become reality in the future are Amasia (the fusion of America and Asia, over the North Pole, 50 to 200 million years hence), Novopangea (the reconstitution of a single supercontinent by the closing of the Pacific Ocean) and Pangea Proxima (in which Australia and Antarctica merge, but stay separate from all other land, which also merges). So it is by mere accident of birth that we, the human race, live on a multi-continent Earth instead of on a planet dominated by a supercontinent, surrounded by a single ocean. How different would human history have looked, if we had shared a single continent? Well, for one, something as history-altering as the Discovery of America would have been impossible.

No area that large could exist in a vacuum on a single-continent Earth. Would Pangea have been beneficial, enabling more trade and cultural exchanges? Or would it have been the death-knell of humankind itself, allowing war and disease to ravage the entire world in one fell swoop? How long before this becomes a grassroots movement? What's for sure is that its borders would look nothing like these, which result from our multicontinental world. How could non-existing coastlines cause a land border between Mexico and Colombia, for instance? But still, I bet you're looking to see whether your country is up or down in this brave, new Pangea, and what its new neighbourhood looks like. Good news if you're Russian: finally, a warm-water port! Or Tibetan: bye bye, China! Bad news if you're claustrophobic, and Malagasy [13] : you are now surrounded by half a dozen neighbouring countries instead of the ocean. Or if you're Swiss, and hate water: you're now in need of a navy [14] . Many thanks to Sam Huddy, Erik Smit and Rikkie Neutelings for sending in this map, found here on Reddit .

The map of future supercontinents found here . The Reunite Pangea t-shirt for sale here . This blog is unaffiliated with the commercial or political aims of whoever sells these t-shirts. _______ [1] From the Greek Παν-γαία, for 'Whole Earth'. Transliteration from Greek to Latin alphabet varies from the pedantic Pangæa over the stodgy Pangaea, to the now commonly accepted (but for some still hideously syncopated) Pangea. Less frequently used is Pangaia, perhaps to prevent confusion with the Gaia hypothesis. That concept posits the Earth as a complex biosphere naturally geared towards some kind of life-enabling balance, the self-regulatory systems of which are akin to those of a living organism. Like the other derivations, this term too is borrowed from the original Greek word for Earth. The prefix pan- is also used in a geopolitical sense, describing the aspiration of certain ethnic, cultural, or religious groups to achieve political union beyond the constrictions of contemporary borders. E.g.: pangermanism, panslavism, panislamism, etc.

↩ [2] Dixit the ultra-chauvinist, one-man insult factory Lord Flasheart, that eerie prefiguration of Nigel Farage , in Blackadder Goes Forth, episode 4 . ↩ Historical perspective [This Dynamic Earth, USGS] Tectonic plates [115 k] The belief that continents have not always been fixed in their present positions was suspected long before the 20th century; this notion was first suggested as early as 1596 by the Dutch map maker Abraham Ortelius in his work Thesaurus Geographicus. Ortelius suggested that the Americas were "torn away from Europe and Africa . . . by earthquakes and floods" and went on to say: "The vestiges of the rupture reveal themselves, if someone brings forward a map of the world and considers carefully the coasts of the three [continents]." Ortelius' idea surfaced again in the 19th century. However, it was not until 1912 that the idea of moving continents was seriously considered as a full-blown scientific theory -- called Continental Drift -- introduced in two articles published by a 32-year-old German meteorologist named Alfred Lothar Wegener.

He contended that, around 200 million years ago, the supercontinent Pangaea began to split apart. Alexander Du Toit, Professor of Geology at Witwatersrand University and one of Wegener's staunchest supporters, proposed that Pangaea first broke into two large continental landmasses, Laurasia in the northern hemisphere and Gondwanaland in the southern hemisphere. Laurasia and Gondwanaland then continued to break apart into the various smaller continents that exist today. In 1858, geographer Antonio Snider-Pellegrini made these two maps showing his version of how the American and African continents may once have fit together, then later separated. Left: The formerly joined continents before (avant) their separation. Right: The continents after (aprés) the separation. (Reproductions of the original maps courtesy of University of California, Berkeley.) Wegener's theory was based in part on what appeared to him to be the remarkable fit of the South American and African continents, first noted by Abraham Ortelius three centuries earlier.

Wegener was also intrigued by the occurrences of unusual geologic structures and of plant and animal fossils found on the matching coastlines of South America and Africa, which are now widely separated by the Atlantic Ocean. He reasoned that it was physically impossible for most of these organisms to have swum or have been transported across the vast oceans. To him, the presence of identical fossil species along the coastal parts of Africa and South America was the most compelling evidence that the two continents were once joined. In Wegener's mind, the drifting of continents after the break-up of Pangaea explained not only the matching fossil occurrences but also the evidence of dramatic climate changes on some continents. For example, the discovery of fossils of tropical plants (in the form of coal deposits) in Antarctica led to the conclusion that this frozen land previously must have been situated closer to the equator, in a more temperate climate where lush, swampy vegetation could grow. Other mismatches of geology and climate included distinctive fossil ferns (Glossopteris) discovered in now-polar regions, and the occurrence of glacial deposits in present-day arid Africa, such as the Vaal River valley of South Africa.

The theory of continental drift would become the spark that ignited a new way of viewing the Earth. But at the time Wegener introduced his theory, the scientific community firmly believed the continents and oceans to be permanent features on the Earth's surface. Not surprisingly, his proposal was not well received, even though it seemed to agree with the scientific information available at the time. A fatal weakness in Wegener's theory was that it could not satisfactorily answer the most fundamental question raised by his critics: What kind of forces could be strong enough to move such large masses of solid rock over such great distances? Wegener suggested that the continents simply plowed through the ocean floor, but Harold Jeffreys, a noted English geophysicist, argued correctly that it was physically impossible for a large mass of solid rock to plow through the ocean floor without breaking up. Rejoined continents [48 k] Undaunted by rejection, Wegener devoted the rest of his life to doggedly pursuing additional evidence to defend his theory. He froze to death in 1930 during an expedition crossing the Greenland ice cap, but the controversy he spawned raged on.

However, after his death, new evidence from ocean floor exploration and other studies rekindled interest in Wegener's theory, ultimately leading to the development of the theory of plate tectonics. Plate tectonics has proven to be as important to the earth sciences as the discovery of the structure of the atom was to physics and chemistry and the theory of evolution was to the life sciences. Even though the theory of plate tectonics is now widely accepted by the scientific community, aspects of the theory are still being debated today. Ironically, one of the chief outstanding questions is the one Wegener failed to resolve: What is the nature of the forces propelling the plates? Scientists also debate how plate tectonics may have operated (if at all) earlier in the Earth's history and whether similar processes operate, or have ever operated, on other planets in our solar system. High School Earth Science/Continental Drift - Wikibooks, open books for an open world High School Earth Science/Continental Drift From Wikibooks, open books for an open world This is the latest reviewed version , checked on 9 November 2016. There is 1 pending change awaiting review.

(+) Quality: minimal 8 Points to Consider An important piece of plate tectonic theory is the continental drift idea. This was developed in the early part of the 20th century, mostly by a single scientist, Alfred Wegener. His hypothesis states that continents move around on Earth's surface and that they were once joined together as a single supercontinent (Figure 6.5). Wegener's idea eventually helped to form the theory of plate tectonics, but while Wegener was alive, scientists did not believe that the continents could move. Figure 6.5: The continents fit together like pieces of a puzzle. This is how they looked 250 million years ago. Be able to explain the continental drift hypothesis. Describe the evidence Wegener used to support his continental drift idea. Describe how the north magnetic pole appeared to move, and how that is evidence for continental drift. Understand apparent polar wander. The Continental Drift Idea[ edit ] Find a map of the continents and cut each one out. Better yet, use a map where the edges of the continents show the continental shelf. In this case, your continent puzzle piece includes all of the continental crust for that continent and reflects the true size and shape of the continent.

Can you fit the pieces together? The easiest link is between the eastern Americas and western Africa and Europe, but the rest can fit together too! Alfred Wegener, an early 20th century German meteorologist believed that the continents could fit together. He proposed that the continents were not stationary but that they had moved during the planet's history. He suggested that at one time, all of the continents had been united into a single super continent. He named the super continent Pangaea, meaning entire earth in ancient Greek. Wegener further suggested that Pangaea broke up long ago and that the continents then moved to their current positions. He called his hypothesis continental drift. Evidence for Continental Drift[ edit ] Besides the fit of the continents, Wegener and his supporters collected a great deal of evidence for the continental drift hypothesis. Wegener found that this evidence was best explained if the continents had at one time been joined together. Wegener discovered that identical rocks could be found on both sides of the Atlantic Ocean. These rocks were the same type and the same age. Wegener understood that the rocks had formed side-by-side and that the land has since moved apart.

Wegener also matched up mountain ranges that had the same rock types, structures, and ages, but that are now on opposite sides of the Atlantic Ocean. The Appalachians of the eastern United States and Canada, for example, are just like mountain ranges in eastern Greenland, Ireland, Great Britain, and Norway. Wegener concluded that they formed as a single mountain range that was separated as the continents drifted. Wegener also found evidence from ancient fossils (Figure 6.6). He found fossils of the same species of extinct plants and animals in rocks of the same age, but on continents that are now widely separated. Wegener suggested that the continents could not have been in their current positions because the organisms would not have been able to travel across the oceans. For example, fossils of the seed fern Glossopteris are found across all of the southern continents. But the plants' seeds were too heavy to be carried across the ocean by wind. Mesosaurus fossils are found in South America and South Africa, but the reptile could only swim in fresh water. Cynognathus and Lystrosaurus were reptiles that lived on land. Both of these animals were unable to swim, let alone swim across wide seas!

Their fossils have been found across South America, Africa, India and Antarctica. Wegener proposed that the organisms had lived side by side, but that the lands had moved apart after they were dead and fossilized. Figure 6.6: Wegener used fossil evidence to support his continental drift hypothesis. The fossils of these organisms are found on lands that are now far apart. Wegener suggested that when the organisms were alive, the lands were joined and the organisms were living side-by-side. Wegener also looked at evidence from ancient glaciers. Large glaciers are most commonly found in frigid climates, usually in the far northern and southern latitudes. Using the distribution of grooves and rock deposits left by ancient glaciers on many different continents, Wegener traced the glaciers back to where they must have started. He discovered that if the continents were in their current positions, the glaciers would have formed in the middle of the ocean very close to the equator. Wegener knew that this was impossible! However, if the continents had moved, the glaciers would have been centered over the southern land mass much closer to the South Pole. Wegener also found evidence for his hypothesis from warm climate zones.

Coral reefs and the swamps that lead to the formation of coal are now found only in tropical and subtropical environments. But Wegener discovered ancient coal seams and coral reefs in parts of the continents that were much too cold today. The coral reef fossils and coal had drifted to new locations since the coal and coral formed. Although Wegener's evidence was sound, most geologists at the time rejected his hypothesis of continental drift. These scientists argued that there was no way to explain how solid continents could plow through solid oceanic crust. At the time, scientists did not understand how solid material could move. Wegener's idea was nearly forgotten until technological advances presented puzzling new information and gave scientists the tools to develop a mechanism for Wegener’s drifting continents. Magnetic Polarity Evidence[ edit ] The puzzling new evidence came from studying Earth's magnetic field and how it has changed. If you have ever been hiking or camping, you may have used a compass to help you find your way. A compass uses the Earth’s magnetic field to locate the magnetic North Pole. Earth's magnetic field is like a bar magnet with the ends of the bar sticking out at each pole (Figure 6.7).

Currently, the field's north and south magnetic poles are very near to the Earth's north and south geographic poles. Some iron-bearing minerals, like tiny magnetite crystals in igneous rocks, point to the north magnetic pole as they crystallize from magma. These little magnets record both the strength and direction of the Earth's magnetic field. The direction is known as the field's magnetic polarity. In the 1950s, scientists began using magnetometers to look at the magnetic properties of rocks in many locations. Figure 6.7: Earth's magnetic field is like a magnet with its north pole near the geographic north pole and the south pole near the geographic south pole. Geologists noted that magnetite crystals in fresh volcanic rocks pointed to the current magnetic north pole. This happened no matter where the rocks were located, whether they were on different continents or in different locations on the same continent. But for older volcanic rocks, this was not true. Rocks that were the same age and were located on the same continent pointed to the same point, but that point was not the current north magnetic pole. Moving back in time, rocks on the same continent that were the same age pointed at the same point.

But these rocks did not point to the same point as the rocks of different ages or the current magnetic pole. In other words, although the magnetite crystals were pointing to the magnetic north pole, the location of the pole seemed to wander. For example, 400 million year old lava flows in North America indicated that the north magnetic pole was located in the western Pacific Ocean, but 250 million year old lava flows indicated a pole in Asia, and 100 million year old lava flows had a pole in northern Asia. Scientists were amazed to find that the north magnetic pole changed location through time! There were three possible explanations for this puzzling phenomenon: (1) the continent remained fixed and the north magnetic pole moved (2) the north magnetic pole stood still and the continent moved (3) both the continent and the north pole moved. The situation got stranger when scientists looked at where magnetite crystals pointed for rocks of the same age but on different continents. They found these rocks pointed to different magnetic north poles! For example, 400 million years ago the European north pole was different from the North American north pole at that same time. At 250 million years, the north poles were also different for the two continents.

The scientists again looked at the three possible explanations. If the correct explanation was that the continents had remained fixed while the north magnetic pole moved, then there had to be two separate north poles. Since there is only one north pole today, they decided that the best explanation had to involve only one north magnetic pole. This meant that the second explanation must be correct, that the north magnetic pole had remained fixed but that the continents had moved. To test this, geologists fitted the continents together as Wegener had done. They discovered that there had indeed been only one magnetic north pole but that the continents had drifted. They renamed the phenomenon of the magnetic pole that seemed to move but actually did not apparent polar wander. This evidence for continental drift gave geologists renewed interest in understanding how continents could move about on the planet's surface. And we know that the magnetic pole wanders, too, so the correct explanation was that both the continents and the magnetic poles move. Lesson Summary[ edit ] In the early part of the 20th century, scientists began to put together evidence that the continents could move around on Earth's surface.

The evidence for continental drift included the fit of the continents; the distribution of ancient fossils, rocks, and mountain ranges; and the locations of ancient climatic zones. Although the evidence was extremely strong, scientists could not think of a mechanism that could drive solid continents to move around on the solid earth and most rejected the idea. Continental drift would resurface after World War II when a mechanism was discovered. Review Questions[ edit ] Why can paper cutouts of the continents including the continental margins be pieced together to form a single whole? How can the locations where ancient fossils are found be used as evidence for continental drift? To show that mountain ranges on opposite sides of the Atlantic formed as two parts of the same range and were once joined, what would you look for? What are the three possible explanations for apparent polar wander when the rocks are all on one continent? If the rocks are on more than one continent, which explanation is the only one likely to be true and why? In the face of so much evidence in support of continental drift, how could scientists reject the idea? Look at a world map. Besides the coast of west Africa and eastern South America, what are some other regions of the world that look as they could be closely fit together?

BBC Earth - Supercontinents join nearly all the Earth's dry land Over 200 million years ago, the continents were joined together. Dr Iain Stewart explains how the Earth's moving tectonic plates resulted in a supercontinent called Pangaea. Supercontinents In geology, a supercontinent is the assembly of most or all of Earth's continental blocks or cratons to form a single large landmass. However, the definition of a supercontinent can be ambiguous. Many earth scientists, such as P.F. Hoffman (1999), use the term "supercontinent" to mean "a clustering of nearly all continents". This definition leaves room for interpretation when labeling a continental body and is easier to apply to Precambrian times. Using the first definition provided here, Gondwana (aka Gondwanaland) is not considered a supercontinent, because the landmasses of Baltica, Laurentia and Siberia also existed at the same time but physically separate from each other. The landmass of Pangaea is the collective name describing all of these continental masses when they were in proximity to one another. This would classify Pangaea as a supercontinent.

According to the definition by Rogers and Santosh (2004), a supercontinent does not exist today. Supercontinents have assembled and dispersed multiple times in the geologic past (see table). The positions of continents have been accurately determined back to the early Jurassic. However, beyond 200 Ma, continental positions are much less certain. Pangea – How God Split the Continents | Genesis and Creation Pangea – How God Split the Continents Posted on December 14, 2009 by saysthelord There is an obscure passage in Genesis that is generally overlooked, but holds what I believe to be great insight into our early world after the flood. Genesis 10:25 states “Two sons were born to Eber: One was named Peleg, because in his time the earth was divided”. I believe this passage describes a time when God supernaturally separated the continents one from another. The Bible says that Peleg (which means divide) was born 100 years after the flood and lived for 239 years. The time frame for the continental split would therefore have been 100 years after the flood until 339 years after the flood.

The division is said to have taken place during his lifetime, but doesn’t say how long it took. God knew before people did The significance of this passage is truly amazing if we stop to examine the implications. Before the age of the sail, there were people and animals on almost every continent. How did they get there? Both creationists and evolutionists agree that there was originally one super continent called Pangea. In the 1800s, evolutionists stated the theory that Pangea split apart 95 million years ago. The Bible, written long before the 1800s, said that the earth was divided. When Columbus sailed to North America in 1492, he found people and animals. Evolutionists didn’t come up with the idea of Pangea until over 300 years later. So, the Bible described an event before its discovery! The fact that the continents split is not disputed by Bible believing Christians or the evolutionary world. When it took place is in dispute. I have heard three versions of the continental split. The first is the evolutionary view, stating that the split took place 95 million years ago.

The second is common in Christendom, which states that the split took place during the Flood. The third is the literal interpretation stated in Genesis 10:25, that it split between 100-339 years after the flood. The evolution position If the evolutionary view is correct, it raises some interesting questions. How did people get here (North America, Australia, Japan, Samoa, the Caribbean, Hawaii, etc) if they evolved after the split? People did not evolve until 2 million years ago (I have heard several estimates, none later than that). No one suggests that we all evolved separately and simultaneously since that idea would be extreme even to an evolutionist. They didn’t sail to those places. The explanation I had always been taught was that they walked to those places. How did they walk if oceans and seas surround the continents? People supposedly crossed the Bering Straight land bridge 15,000 years ago. The water there is a minimum of 50 feet deep. They say the ice age caused the ocean levels to drop since the water was frozen and on top of the continents, thus exposing dry land for people and animals to walk across.

Sounds logical enough until you examine the details more closely (something we don’t often do). Doing the math yielded some interesting results. A 50 foot drop in the oceans would fill 1117 Lake Michigans! That would equal 1,318,248 cubic miles of water. The volume would increase by 8.7% when it is frozen resulting in 1,432,935 cubic miles of ice. That much ice would cover all dry land on earth with 130 feet of ice! Since the ice age was a northern hemisphere phenomenon, there would be about 200 feet of ice covering our world here in Wisconsin. I find that hard to believe. What natural phenomenon would cause that much ice to cover everything? The July sun would never allow it. Then, how would these people cross that area since it was covered with 200 feet of ice? Evolutionists say that area remained unglaciated! Warm Pacific winds kept that area dry, even though it was cold enough to create such a calamity? It seems like these explanations are invented to make these unlikely scenarios feasible.

Why would ancient man go to such a barren place when the entire northern hemisphere was supposedly like the Arctic Circle? Where would they find food? If the following animals did not evolve until after the continental split 95 million years ago, then how do they explain their presence in the New World: the American Lion, the American Rhinoceros, the American Cheetah, the Mastodon, the American Zebra, Camelops and the Cuban Ground Sloth? As with man, they supposedly walked across the frozen desolate Bering Straight with no food in sight! This to me seems very unfeasible. As I mentioned before, either these animals evolved simultaneously in two different places or we are missing something. By the way, remember I mentioned earlier that the ocean levels would have had to drop 50 feet minimum to create a land bridge to Russia? Well, the ocean would have had to have dropped 500 feet to create a land bridge from Florida to Cuba. A 500 foot drop would have created not 200 feet of ice on North America, but 2000! Sloths do not swim! There must be another explanation for all of this.

Before I get to that I will discuss the next possibility. Pangea split during the Flood? The second explanation is that the splitting of the earth occurred during the flood. If this is true then the Christian just inherited all of the same problems associated with the evolutionary Pangea split. How did Koala bears get from Turkey to Australia? How did the people get here? The common interpretation is that Genesis 10:25 is it is actually referring to the people of the earth when it says “the earth was divided”. I looked up the word ‘earth’ in the Hebrew Old Testament. It occurs 738 times. It can refer to people. Just to be curious, I read every verse that uses that word. The word is overwhelmingly used to describe the planet. Not one of the other occurrences in Genesis (86 other times) refers to people. In fact, the overwhelming majority of occurrences in the entire Old Testament refer to our world, not the people. You see, the discussion of Peleg occurs before and after the Tower of Babel. The Bible does not explicitly state when the Tower of Babel took place.

So, the easy explanation is when God says the earth was divided, He must have been making reference to when the people were scattered. I find it interesting to note that in the description of the Tower of Babel, it says the people were scattered, which is a different word than ‘Peleg’ which means divided. If we take the Bible at face value, then the people were scattered and the earth was divided. I believe it means what it says. We all spoke one language and had access to each other because of the single land mass. But because of our sin, God separated us by language and geography. This action limits the effects of sin, and allows one group to rise against another if one gets too wicked. This division of the continents saved this world from Hitler in 1945. What the Bible says After the flood, God confused the languages. People and animals walked to every part of the earth. Then God split the land. This explains why people and animals and American Lions and Cuban ground sloths are found everywhere. And this explanation came before we knew of the continental split. This is just like Job 26:7 which state that God suspends the earth over nothing!

The ancients did not have spaceships, but Job knew the earth floated through space. Before you concern yourself with the earthquakes that would have resulted from such a split of the earth, review Joshua 10:13. This is the real day the earth stood still. Since we are moving at over 1000 miles an hour at the equator, God must have supernaturally dampened the effects when He suddenly stopped the earth from rotating. He must have done a similar work when He split the earth in Peleg’s time. Like this:

Question: What name is given to the original single continent on Earth that has split into the continents we have today?
Answer: PANGEA